Block-making machine



May 15, 1928./

2 sheets-snee: 1`

F. J. sTRAUB BLOCK MAKING MACHINE Filed No'v.' 16. 1926 1,669,682 F. J. STRAUB BLOCK MAKING MACHINE Filed Nov. 16, 1926 2 Sheets-Sheet 2 INVENTOR May 15, 1928.

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UNITED' `'STATI-:ls

PATENT l oFF1cE.-

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` gnccx-MAKING MACHINE..

Anuman mea November 1e, 162e. semi No. 14am.

M invention refers to improvements in bloc -ma'king machines for the manufacture of concrete building blocks and similar articles. Ordinarily, the usual practice is to com ress the aggregate withln a l forming mol by means of vertically .operating gravitating tamps, which fall uponl the aggregate as it 1s charged into the-mold, and upon the temporarily stationary bottom plate or pal-v `let rest. Y t

Such practice is objectionable for several reasons. j u Where the preliminary charge of aggregate y in the bottom of the mold is of any material rdepth, or with rapid filling, the lifting of the tamps for the necessary length of stroke to first tamp the lowermost strata is excessive and slow, and that portion of the block is apt to be too close and spongy. l

Another objection incident to the long travel of the tamps through the whole depth of the mold, is the destructive action due to the wear of the tamps against their inner sides, while the aggregate itself exerts a considerable frictional abrasion against the mold and cores, resulting in rapid wear.

Such operation is objectionable in that the variation in the total drop of the tamps results in a material difference in uniformity of density of the block, while the wear on the mold in time is so great as to seriously vimpair its dimensions, resulting in uneven and unsymmetrical blocks.

In my present invention I secure uniformity of compression with a practically uniform stroke of the tamps both as to time and distance, by a preliminary filling and tam ing at the top of the mold, and maintaining the tamping at such portion throughout the whole operation.

This is effected by gradually lowering the mold bottom, i. e., the pallet and its rest, as the loose aggregate is delivered and tamped, the entire tamping being done within an upper limited zone, against the downwardly receding block in process.

In the drawings, showing portions only of a complete block molding and compressin machine,

ig. 1 is a vertical sectional view of a molding machine and the pallet supporting the pallet support;

and lowering mechanism at the commencement of the operation; 4 Fig. is a similar view showing the moldmg cavity completely filled;

Fig. 3 is a slmilar view showing ejection of the finished block;

Fig. 4 is a detail cross section on the line IV- V of Fig. 3, showing connection between the lowering plunger and the stem of Fig. 5 is a perspective view of one of the formed blocks. f

In the drawings, the usual walls 2of the mold are fixedly mounted upon a base plate or core bridge 3, which 'maintain the upwardly extending cores 4 for formation of the inner and endmost openings 5 of the A vertically movable plate or pallet rest 6 normally fits within the mold, with clearance openlngs surrounding the cores for free movement. Such plate is raised and lowered in any adaptable manner, as by osts 7 actuated upwardly and-downward y by any suitable means, as levers.8 and pitman 9. for graduated lowering durin formation of the block and upward disc arge or ejection thereof.

The usual pallet 1'0, also having clearance openings for the cores, rests loosely on the core bridge 3 for supporting and removal of t-he formed block, in the usual way.

vSecured underneath the core bridge 3 by flanges 11 is a vertically arranged cylinder 12 having a plunger receiving cavity 13 for plunger 14 and a lower fluid holding reservoir 15 connected with the base of the cylinder by flanges 16, 17.

A ball valve 18 closes a valve seat between plunger cavity 13 and an upwardly conducting supply conduit 19 projecting downwardly into reservoir 15 below the level of fiuid therein, as shown.

The reservoir 15 is provided with any suitable filling connection for a suitable liquid, as oil, and has an aii vent o ening 20 to prevent vacuum on upstroke o the plunger.

The cylinder 12 is also provided with a lateral opening at its upper ortion providing for esca e of air when Erst filled with liquid,and c osed by` a plug 21.

A slow or regulated flow b -pass port 22 leads through valve-controlle port 23 bac'k from the interior of cylinder 12 to reservoir 15 for regulated lowering of the plunger and the pallet rest 6.

. Port 23" is controlled by needle valve 24 of stem 25, threaded in the base of t-he cylinder with suitable packing 26, as shown.

Plunger 14 extends upwardly through the upper end of cylinder 12 surrounded by suitable packing 27 and is provided with a con? trall bore A28 for reciprocating movement therein of a plunger 29.

Said plunger is fixedly connected centrally to the pallet rest plate 6 by a riveted drical wallof plunger 14. By such construction the late 6 has a limited range of movement in ependent of plunger 14, so that on upward movement ofplate 6 key 32 will lirst 'move through the slot 31 until it engages its upper. end.

Thereafter the plunger 14 will be lifted as in Fig. 3, with a clearance. between the toppof the suspended plunger and the bottom of plate 6, until plate 6 has arrived at the top of the mold, for discharge ofl the block.

On the other hand, when plate 6 is reversed in lowering for the next operation, it will move downwardly to the same extent, through the excessilength of the slot, until the bottom of the plate abuts .against the upper end of the outer plunger, as in Fig. 1.

Such preliminary lowering of the pallet plate and pallet 10 is just sufficient to p-rovide the necessary depth in the mold for the first application and tamping of the aggregate, after which the lowering of thepallet plated is retarded by the"throttled flow of liqui On upward movement'of plun er 14 valve 18 will be unseated, allowmg t e Huid in conduit 19 to pass freely upward from the reservoir, following the plunger by suction. On reverse movement of the plunger, valve 18 will seat, and downward movement of the plunger will be comparatively slow, under regulated control of port 23.

During such lowering the aggregate. is supplied, with continued tamping by the usual tamps 33, unti1 the plate 6 is' lowered to the bottom of the mold, as in Fig. 2;

' Likewise, it will be observed, the tamping action is maintained only at the top portion of the receding body of aggregate, the tamps rising and falling with substantial uniformity, and making impact with the aggregate at and immediately below the to of the mold only. The advantages of the invention may also be secured by tamping the aggro-- gate immediately above the top of the mold.

The result of such operation is that the block is tamped uniformly and evenly throughout its entire depth, with a substantially uniform lift and drop of thetamps, and avoiding the objections noted.

The density of the block may be easily regulated by controlling the speed of downward movement of plunger 14 as described, so that blocks of uniform consistency may be readily and continuously made.

-Thus with slow lowering and numerous tamping strokes, very dense blocks may be made, while less dense or more porous blocks may be made with a moregrapid rate of lowermg.

The operation will be readily understood` v.

from the foregoing'description. A finished block having been ejected and carried away on its pallet, another pallet is placed on-l plate 6 which lowersuntil arrested by contact against the top of plunger` 14.

Thereafter the'relatively slow and regular lowering of the pallet plate carries the block downwardly as it is increasingly formedvand tamped, with finalY removal ofv any loose surplus and pressure of the top surface, as in usual practice.

The formed block is then quickly' raised and removed, when the operation is repeated.

It will be understood that the invention may be utilized with any similar or standard form of block making machine, independent of the particular shape, dimensions, or other limitations of the block or the aggregate used.

By varying the opening of port 23, the lowering of the plunger 14 may be easily and accurately regulated, either for fast or slow movement. Thus in case of a very wet mix the valve 24 may be opened for free escape of oil, with corresponding quick lowering of the aggregate within the mold, while with a drier mixture, the speed may be correspondingly slow, as desired.

Also that various changes or modifications may be made by the skilled mechanic in detail construction or otherwise, without departing from the invention as hereinafterv loo mechanism centrally below the plate for gradually lowering it as aggregate is furnished to the mold.

2. In block making apparatus, a forming` mold having a vertically movable bottomv plate, and means centrally below the plate for interposing a graduated resistance to the plate under pressure of the aggregate in the mold.

8. In block making aparatus, a forming mold having a vertica y movable bottom plate, means for lifting the bottom plate, and valve controlled fluid resistance mechanism for interposing lowering resistance lto the plate and aggregate thereon under impact of compressing mechanism.

4. In block making apparatus, a forming mold having a vertically movable bottom plate, a fluid containing plunger casing provided with circulation controlling valves, a plunger therein, and means connecting the plunger with the bottom plate.

5. In block making a paratus, a forming mold having a vertlca ly movable bottom plate, a Huid containing plunger casing provided with circulation controlling valves, a plunger therein, and means connecting the plunger with the bottom plate providing for a limited relative movement of the plunger and late.

6. n block making a paratus, a forming mold having a vertica ly movable bottom plate, a fluid containing plunger casin provided with circulation controllng va ves, a plunger therein and a stem secured to the ottom plate having limited telescoping movement with relation to the plun er.

`'Z'. In block making apparatus, a orming mold having a vertica plate, means for elevating the bottom plate,

ly movable bottomA a plunger casing having a bottom reservoir and intervening valve controlled po a plunger therein, and a relatively mova le stem secured to the bottom plate and having slotted connection with the plunger.

8. The combination in a block molding machine, of a mold casing, a supporting core bridge therefor, a vertically movable pallet rest within the mold, means for lifting the pallet rest, a series of gravitating tamEs operable within the upper portion of t e mold, a lunger casing extending below the core bri ge and trollcd fluid circu ation ports, a plunger in the casing, and a relatively movable stem secured to the allet rest and having slotted connection with) the plunger providing for a limited amount of independent movement of the pallet rest.

9. In molding apparatus as described, the combination with an upper plunger casing, of a lower fluid containing reservoir, a central conduit leading from the bottom of the casin into the reservoir having an intervening check valve, and a valve controlled byass port leading from the base of the cas- Ing to the reservoir around the check valve.

In testimony whereof I hereunto aiiix my signature. l

FRANCIS J. SITRAUB.

rovided with valve con 

